Open AccessAnalytical characterization of four wave mixing effect in direct-detection double-sideband OFDM optical transmission systems
Author(s) -
Tiago M. F. Alves,
Adolfo V. T. Cartaxo
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.008598
Subject(s) - sideband , four wave mixing , optics , physics , expression (computer science) , degenerate energy levels , modulation (music) , transmission (telecommunications) , multiplexing , orthogonal frequency division multiplexing , mixing (physics) , subcarrier , telecommunications , nonlinear optics , computer science , channel (broadcasting) , acoustics , quantum mechanics , laser , microwave , programming language
A closed-form expression for the variance of the four-wave mixing (FWM) induced in each subcarrier of a double sideband orthogonal frequency division multiplexing (OFDM) system employing direct detection is proposed and validated. Particularly, using a small signal analysis, equivalent transfer functions that characterize the frequency response of the FWM effect are derived taking into account the walkoff effect between the modulated pump waves and the FWM wave. The accuracy of the variance estimates provided by the closed-form expression is assessed for different sets of system parameters. The closed-form expression provides good variance estimates of the FWM-induced degradation caused by degenerate and nonsymmetric nondegenerate FWM components. For symmetric non-degenerate FWM components, the proposed expression provides reliable but pessimistic variance estimates, not exceeding the actual FWM variance in 1.5 dB for modulation indexes of interest.